由山东教育出版社出版、江苏省2005年8月第一版普通《高中课程标准实验教科书地理(必修·第一册)》的第23页活动:借助手表,可粗略地确定南北方向。在北半球,把手表平置,时针指向太阳方向,在中午12点前,按顺时针,沿时针与12点刻度线之间所成夹角的角平分线方向为南方;在中午12点后,按逆时针,沿时针与12点刻度线之间所成夹角的角平分线方向为南方。请你思考,借助手表辨别方向往往受到哪些条件限制?为什么?我认为该处内容的设计总体很好,拓宽了学生的知识面,激发了学生的思维,但也有值得商榷的地方。具体表现在以下两个方面:一、该处的12点为“什么时间”?我认为12点应当是观察地的地方时,这一点教材必须交代清楚为好,否则就会出现较大的偏差。例如,我国东西跨越了5个时区,如果利用北京时间手表来测量新疆某地的方向就会出现较大的偏差。若北京时间为12点时,我国西部某地有 From Shandong Education Press, Jiangsu Province, August 2005 First Edition General High School Curriculum Standard Experimental Textbook Geography (Compulsory Volume I) "Page 23 Activities: With the aid of a watch, the north-south direction can be roughly defined. In the northern hemisphere, the watch flat, the hour hand points the direction of the sun, before 12 o’clock in the clockwise, along the angle between the hour hand and the 12-point scale angle bisector direction south; at 12 o’clock in the afternoon, Press counterclockwise, along the 12 o’clock hour mark and the angle between the angle formed bisector of the direction of the south. Why do you think, with the help of the watch to identify the direction is often subject to what conditions and why? I think the design of the Department’s overall good, broaden the students’ knowledge, inspire students thinking, but there are also debatable. Specifically in the following two aspects: First, the 12 o’clock for the When I think 12 should be the place to observe, this textbook must explain clearly as well, otherwise there will be a larger The deviation. For example, our country has crossed 5 time zones. If we use the Beijing time wristwatch to measure the direction of a place in Xinjiang, there will be a big deviation. If Beijing time is 12 o’clock, there is a place in western China